It has long been known to provide ostomy appliances with relatively rigid convex pressure rings for the purpose of increasing stomal protrusion when such an appliance is worn, thereby aiding in the discharge of effluent directly into the pouch and also prolonging the effectiveness of the adhesive seal between the faceplate and peristomal skin surfaces. Reference may be had to U.S. Pat. Nos. 4,834,731, 5,618,276, 5,607,413, 5,730,735 and 5,501,678 for examples of appliances having such pressure rings. It has also been known to provide rigid convex adapters that may be attached to conventional ostomy faceplates as disclosed, for example, in U.S. Pat. Nos. 4,834,731, 5,004,464, 4,219,023, and 5,163,930.
A premise underlying the design of such convex faceplates and adapters is that a patient""s stoma is circular in outline, but studies have shown that is not necessarily the case. In one such study it was noted that stomas not only vary widely in size but that only 58% could be considered circular in shape with 42% being regarded as elliptical or irregular. Nordstrom, G. M. et al, Local Status of the Urinary Stomaxe2x80x94The Relation to Peristomal Skin Complications, Scand. J. Urol. Nephrol. 24:117-122 (1990). The possibility that a stoma may be non-circular in shape is also noted in European published application 0 888 760 A1, although that application relates to a planar faceplace rather than a convex one.
Since convexity has been achieved in the past by providing a faceplate or adapter with a relatively stiff plastic element capable of causing stomal protrusion, such a ring has the capability of causing considerable wearer discomfort should the opening of the ring fail to match the shape of a wearer""s stoma, or should direct contact between such a ring and a wearer""s stoma occur when the wearer bends sharply forward, change positions, or simply moves about.
While it has been known to provide ostomy faceplates with soft, pliant barrier rings, or to supply soft gaskets that may be attached to such rings, such faceplates and gaskets do not function as convex pressure rings. See, for example, U.S. Pat. Nos. 4,213,458 and 4,710,182. Such faceplates/gaskets are commonly formed of a soft flowable material such as karaya, with such material serving as a sealant which flows or is displaced by finger pressure and use into contact with a stoma to prevent leakage and avoid the excorciating effects that may result if stomal effluent contacts peristomal skin surfaces.
The present invention is concerned with a convex adapter that overcomes the shortcomings of prior convex faceplates and adapters and, specifically, one which may be easily and quickly adjusted in size and shape to match the size and shape of a wearer""s stoma. The adapter includes a ring formed entirely of moisture-absorbing skin barrier material that is adhesive, soft, rubbery, non-disintegrating upon hydration, non-flowing, and shape-recoverable following compressive deformation. To achieve such objectives, the barrier material should have a continuous phase of an elastomeric adhesive blend including a styrene-olefin-styrene rubber, and a discontinuous phase of hydrocolloid particles dispersed throughout the rubbery adhesive phase.
An important aspect of this invention lies in providing the convex surface of the adapter ring of barrier material with a stretchable cover film that extends outwardly a substantial distance beyond the edges of the ring. The cover film must be removable from the ring and is preferably transparent, or at least translucent, so that the ring""s outermost edges, and preferably the opening of a faceplate to which the adapter is to be adhered, may be seen through the film. In addition, the opposite surface of the barrier ring is covered by a removable release sheet which, unlike the cover film, is substantially non-stretchable. The release sheet is preferably of the same size and shape as the cover film, but both should be substantially larger than the faceplate to which the adapter ring is to be attached so as to facilitate removal of the cover film after the faceplate and convex adapter ring have been joined together.
The invention also includes what is believed to be a distinctive method of using the convex adapter. It is well known to provide the adhesive faceplate of an ostomy appliance (either a one-piece appliance or a two-piece appliance) with a small circular starter opening which may then be cut to larger size (with scissors) to match the size and shape of a patient""s stoma. Alternatively, the faceplate may be manufactured with an opening sized and shaped (e.g., oval-shaped) to approximate the size and shape of the patient""s stoma. In either case, the present method involves reshaping or reforming the adapter ring to match the size and shape of the opening of the faceplate. To that end, a user first strips away the non-stretchable release sheet and then grips the adapter ring, covered only on one side by the stretchable cover film, and reforms the ring by pulling outwardly in opposite directions in the general plane of the ring so that its stoma-receiving opening approximates the size and shape of the faceplate opening. The convex adapter ring is then secured to the faceplate, the cover film is peeled away, and the composite faceplate/adapter is adhesively secured to the patient""s peristomal skin surfaces.
Other advantages, features and objects of the invention will become apparent from the specification and drawings.